If I execute the following:
<< Miscellaneous`PhysicalConstants`
<< Miscellaneous`Units`
Convert[GravitationalConstant*EarthMass/EarthRadius^2, Meter/Second^2]
I get 9.7997 Meters/Sec^2 - which is a rather inaccurate value for g!
I wonder if the EarthMass value has been calculated from one value of
G and a different value has been used in the package (G is hard to
measure and its accepted value has shifted somewhat).
I got that result while demonstrating Mathematica to a colleague, so
it was a bit embarrassing!
David Bailey